Abstract: The L₂ limestone water from FZ1-2^# borehole in Henyuang Company II6112 working face is 50 m³/h. Due to the absence of timely grouting, the casing is broke and a wide range of floor water inrush nearby drilling roadway appears under the mine pressure. The method of using decentralized small-diameter casing is not success, the grouting effect of curtain-grouting method after hydrophobicity and depressurization is not obvious, the eventual adoption is to excavate broken position methods to deal with the broken pipe drilling, which is effective with significant treatment effect and successfully treats floor water inrush caused by casing fracture.